fix: generate types once to separate lib/types directory

Previously, DTS files were generated twice (for ESM and CJS) which
caused out-of-memory errors in CI due to worker memory limits.

Changes:
- Generate types once to lib/types/ using dts: { only: true }
- ESM and CJS builds no longer generate their own types
- Simplify package.json exports to use single types path
- Extract shared entry config to reduce duplication

This follows the pattern used by Stripe SDK and Hono, where types
are kept in a separate directory and shared between ESM/CJS consumers.

Build time reduced from ~48s to ~22s.

Author: nicknisi

package.json

@@ -14,7 +14,7 @@
   "type": "module",
   "main": "./lib/cjs/index.cjs",
   "module": "./lib/esm/index.js",
-  "types": "./lib/esm/index.d.ts",
+  "types": "./lib/types/index.d.ts",
   "files": [
     "lib/",
     "package.json"
@@ -75,10 +75,7 @@
   },
   "exports": {
     ".": {
-      "types": {
-        "require": "./lib/cjs/index.d.cts",
-        "import": "./lib/esm/index.d.ts"
-      },
+      "types": "./lib/types/index.d.ts",
       "workerd": {
         "import": "./lib/esm/index.worker.js",
         "require": "./lib/cjs/index.worker.cjs"
@@ -105,19 +102,13 @@
       "default": "./lib/esm/index.js"
     },
     "./client": {
-      "types": {
-        "require": "./lib/cjs/index.client.d.cts",
-        "import": "./lib/esm/index.client.d.ts"
-      },
+      "types": "./lib/types/index.client.d.ts",
       "import": "./lib/esm/index.client.js",
       "require": "./lib/cjs/index.client.cjs",
       "default": "./lib/esm/index.client.js"
     },
     "./worker": {
-      "types": {
-        "require": "./lib/cjs/index.worker.d.cts",
-        "import": "./lib/esm/index.worker.d.ts"
-      },
+      "types": "./lib/types/index.worker.d.ts",
       "import": "./lib/esm/index.worker.js",
       "require": "./lib/cjs/index.worker.cjs",
       "default": "./lib/esm/index.worker.js"

tsup.config.ts

@@ -1,31 +1,42 @@
 import { defineConfig } from 'tsup';
 import { fixImportsPlugin } from 'esbuild-fix-imports-plugin';
 
+const entry = [
+  'src/**/*.ts',
+  '!src/**/*.spec.ts',
+  '!src/**/*.test.ts',
+  '!src/**/fixtures/**',
+  '!src/**/*.d.ts',
+  '!src/**/test-utils.ts',
+];
+
 export default defineConfig([
-  // ESM build
+  // Types only
   {
-    entry: [
-      'src/**/*.ts',
-      '!src/**/*.spec.ts',
-      '!src/**/*.test.ts',
-      '!src/**/fixtures/**',
-      '!src/**/*.d.ts',
-      '!src/**/test-utils.ts',
-    ],
+    entry,
     format: 'esm',
-    outDir: 'lib/esm',
-    splitting: false,
-    target: 'es2022',
-    sourcemap: true,
-    clean: true,
+    outDir: 'lib/types',
     dts: {
+      only: true, // Only emit declarations, no JS
       resolve: true,
       compilerOptions: {
         lib: ['dom', 'es2022'],
         types: ['node'],
       },
     },
     bundle: false,
+  },
+  // ESM build - no types
+  {
+    entry,
+    format: 'esm',
+    outDir: 'lib/esm',
+    splitting: false,
+    target: 'es2022',
+    sourcemap: true,
+    clean: true,
+    dts: false,
+    bundle: false,
     outExtension() {
       return { js: '.js' };
     },
@@ -34,32 +45,19 @@ export default defineConfig([
     },
     esbuildPlugins: [fixImportsPlugin()],
   },
-  // CJS build
+  // CJS build - no types
   {
-    entry: [
-      'src/**/*.ts',
-      '!src/**/*.spec.ts',
-      '!src/**/*.test.ts',
-      '!src/**/fixtures/**',
-      '!src/**/*.d.ts',
-      '!src/**/test-utils.ts',
-    ],
+    entry,
     format: 'cjs',
     outDir: 'lib/cjs',
     splitting: false,
     target: 'es2022',
     sourcemap: true,
-    clean: false, // Don't clean, keep ESM files
-    dts: {
-      resolve: true,
-      compilerOptions: {
-        lib: ['dom', 'es2022'],
-        types: ['node'],
-      },
-    },
+    clean: false,
+    dts: false,
     bundle: false,
     outExtension() {
-      return { js: '.cjs', dts: '.d.cts' };
+      return { js: '.cjs' };
     },
     esbuildOptions(options) {
       options.keepNames = true;